The present invention relates to identification of land vehicles.
Automatic remote identification of vehicles is useful for many purposes, but existing technologies are inadequate. A license plate is the standard identifier, but license plates cannot be read reliably by automatic equipment. The relationship between a vehicle and its license plate changes each time that the owner or the state of registration changes, complicating database access.
The E-Z Pass system now in use in the northeastern U.S. equips each vehicle with a radio tag for remote identification, and identifies passing vehicles with automatic radio transponders. However, such radio tags are unreliable and the system requires a back-up system of license plate imagingxe2x80x94which is itself unreliable. With radio tags, only one vehicle at a time can be identified and the identification range is limited to about eight feet of roadway. E-Z Pass uses 900-MHz radio waves, which about one foot long; such long waves cannot be beamed back from the vehicle, which must therefore be near to the sensor.
Bar codes have also been used for identifying vehicles at toll booths, but bar codes have several drawbacks (discussed below) and cannot be read at any distance or from different directions.
Under federal law (49 C.F.R. xc2xa7565), each vehicle has a Vehicle Identification Number (VIN) that is permanently and uniquely assigned to that vehicle. The VIN would be a better identifier, when searching for a stolen or wanted vehicle, than a license plate number. However, the VIN is written in tiny characters and can only be read when a vehicle is stopped. Like a license plate, a VIN plate is easy to alter or fake.
Ideally, it would be possible to read the VIN of any vehicle from a distance, rapidly and automatically, and it should be difficult to alter or fake that VIN reading. But this has been impossible prior to this invention.
This invention determines the identity of any vehicle instantly, from any distance, and with high accuracy, using available and inexpensive technology. The rapidity and accuracy of the invention will make possible a number of applications, some of which are discussed below.
Basically, a vehicle identifier (preferably the VIN) is encoded into a flickering LED lamp mounted on the vehicle. The flickers are preferably pre-set at the factory to radiate the VIN in a binary digital format: the lamp when lit signifies logical xe2x80x9c1xe2x80x9d and when off signifies logical xe2x80x9c0xe2x80x9d. Each character of the VIN is encoded by a few digital bits according to a code, and transmission of the whole VIN is almost instantaneous. An ordinary LED, of the type already used for brake lights in many vehicles, is capable of turning on and off quite rapidly and can flicker out a complete VIN in a small fraction of a second.
A light-sensing detector, aimed at the flickering lamp, can read the VIN using the same technology that already reads bar codes at every store checkout. Bar code scanners sort out flickering light patterns from background noise, decode the flickering, and access a databank; the detector of this invention does exactly the same thing.
Because light sensors are highly directional, a vehicle with a flickering lamp can be identified from almost any distance by using a telescopic detector.
The flickers are preferably emitted intermittently, so that their flickers will not overlap and the VIN""s of a group of vehicles can be read at the same time; but the flickers can still be repeated many times each second from each vehicle. This means that all of the vehicles in a traffic jam, or all the vehicles passing one point on a busy interstate, can be identified and registered.
The VIN read by the detector can be used to alert authorities that a particular vehicle is at a detector, to access databanks containing information about a vehicle, or to register that the vehicle has passed some checkpoint (e.g., an automatic toll booth or the entrance to a parking garage).
The electronic circuits that drive the flickering lamp are less complex than those of a four-function calculator or a digital watch. The invention can be made with off-the-shelf components in a very small package. If mass-produced, it could be put entirely onto a single silicon chip. The cost of making and installing the flickering lamp will be small, about a dollar. The detectors, too, use available and inexpensive technology.
The invention can increase theft deterrence and speed recovery of stolen vehicles. Once a vehicle is reported as stolen, its VIN number will be put into a database. Automatic detectors, that are mounted on police cars or along traffic routes, will continuously scan for VIN numbers on the list and notify the authorities within seconds whenever a vehicle""s LED flickers out a VIN in the stolen-car database.
The flickering LED""s that encode the VIN can be mounted on the side of the vehicle and/or incorporated into red LED brake lamps or running lamps. Because of the high flickering rate, the output will appear steady, just as a movie or TV image, that is actually flickering, appears steady. Infrared LED""s, like those used in a TV remote, can be employed to make the flickering invisible.
The memory chip encoding the VIN can be placed where it is difficult to tamper with, and/or where tampering will be evident, and the LED and its circuit can be potted (embedded in epoxy) to prevent tampering. To fake the flickers will require of thieves electronic memory-chip programming and construction of an electronic circuit, and tampering will be evident without cosmetic bodywork after installation. Alternatively, especially for after-market use, the flickering unit can be made easy to install and/or remove.
This invention can include augmented VIN""s with an extra, secret character known only to authorities; that will allow detection of faked VIN""s by consulting a central agency having a list of valid VIN""s.